Pressure booster

Abstract

In a pressure booster having a cylinder mechanism, a floating mechanism is disposed between pistons and a piston rod, the floating mechanism being capable of absorbing offset (off centered) loads that are imposed on the pistons from the piston rod. The floating mechanism is constituted from swing bolts connected to both ends of the piston rod, support plates mounted onto end surfaces of the pistons and which swingably support the swing bolts therein, and fixing plates disposed between the ends of the piston rod and the support plates.

1. A pressure booster having a supply port for supplying a pressure fluid, an outlet port through which a pressure fluid that has been increased in pressure is output, and a discharge port for discharging exhausted pressure fluid, wherein by a reciprocating movement of a pair of pistons that are connected to a piston rod and disposed respectively for displacement inside a pair of cylinder tubes, the pressure fluid that is introduced from said supply port is increased in pressure and output from said outlet port, comprising:
 a cylinder mechanism having a pair of cylinder tubes equipped with cylinder chambers to which pressure fluid is supplied, a pair of pistons disposed for displacement inside said cylinder tubes, and a piston rod connected to both of said pair of pistons; 
 a center unit disposed between said cylinder tubes and having a switching section therein for switching a state of communication of the pressure fluid between said supply port and said outlet port and said cylinder chambers; and 
 an offset absorbing mechanism disposed between said pistons and said piston rod, which is capable of absorbing an offset occurring between axial centers of said pistons and an axial center of said piston rod, 
 wherein said offset absorbing mechanism includes a swinging member disposed between said pistons and said piston rod, said swinging member being swingably displaceable with respect to said pistons accompanying offset of said piston rod. 
 
     
     
       2. The pressure booster according to  claim 1 , wherein said offset absorbing mechanism comprises:
 a supporting member mounted on an end surface of said pistons, which swingably supports said swinging member; and 
 a recess formed in the end surface of said pistons into which said swinging member is inserted. 
 
     
     
       3. The pressure booster according to  claim 2 , wherein said offset absorbing mechanism includes an abutment member disposed on said piston rod and confronting said switching section, said abutment member abutting against a push rod of said switching section at a displacement terminal end position of said pistons. 
     
     
       4. The pressure booster according to  claim 3 , wherein a clearance (C 2 ) separated by a predetermined distance along an axial direction of said pistons is provided between said supporting member and said abutment member. 
     
     
       5. The pressure booster according to  claim 2 , wherein said recess is disposed centrally on an axis of said pistons. 
     
     
       6. The pressure booster according to  claim 5 , wherein a clearance (Cl) is provided between said recess and said swinging member in a perpendicular direction with respect to an axial direction of said pistons, said swinging member being disposed displaceably inside of said recess. 
     
     
       7. The pressure booster according to  claim 5 , wherein a damper made of an elastic material is disposed on an end of said swinging member, said damper abutting against an inner wall surface of said recess.